Solar energy is a prime source of thermal energy. One example of the use of thermal energy conversion into mechanical power is the steam engine. Another example of the use of thermal energy conversion into mechanical power is the steam turbine. However, on a scale comparable to the use of fossil fuels for the provision of thermal energy, the use of solar energy to produce mechanical power is almost nonexistent. Therefore, there is a need for improvement in the method and apparatus to attain mechanical power from thermal energy, and there is a need for improvement in the method and apparatus to store thermal energy.